we first heard about this on npr, and had no idea it was going on. here's abc's jon karl. >> reporter: we took a journey to the heart of the u.s. mint in philadelphia. down long corridors, into oversized elevators and through doors, lots of doors, for a lesson on how to lose money while making money. it sounds a little like vegas around here, except the coins never stop coming. this is the presidential dollar coin. they're making them to honor every dead president, but nobody seems to want them. not even the one for rutherford b. hayes. rutherford b. hayes, hot off the press. literally, these coins are still warm. made of manganese brass, they coco 32 cents a pop to make. the mint can make 1.8 million a day. do the math. that's nearly $600,000 a day. because almost nobody uses these things, most go directly into storage. we found a bunch of them 100 miles down the road in a vault. here at the federal reserve in baltimore, the coins are packed into plastic bags stacked one on top of each other all the way up and down this aisle. several aisle of them,